A cellular handset or user equipment (UE) is a battery-powered wireless device that communicates with one or more base stations (BSs), such as an eNodeB. A cellular handset can be in one of two modes, an idle or a connected mode. In the idle mode, the UE can operate in a discontinuous reception (DRX) mode. In accordance with some standards governing cellular handset operation, in the connected mode, the UE can operate in a continuous reception mode or DRX mode. During the DRX mode, the handset can enter a sleep mode and can wakeup to detect periodic control messages. When a cellular handset or UE enters the sleep mode, the UE can conserve the energy stored in the battery and extend the standby and connect time of a cellular handset.
A cellular handset may periodically awaken or exit the sleep mode to test for a paging indicator or control message from a base station. The indicator or message can show that a message from a base station is available for the cellular handset. The cellular handset may make brief, repeated transitions from the sleep mode to an active or connect mode, and vice versa, when checking for messages. The cycle of sleep and connect mode transitions can be called standby mode.
A cellular handset consumes a relatively small amount of power during the sleep mode. When a cellular handset exits the sleep mode, the increased power consumption shortens the remaining standby and connect time.